Low-resistive metal/n+-InAsSb/n-GaSb contacts

We present low-resistive electrical contacts to n-type GaSb with Te doping of 5 x 10(17) cm(-3) using a Ti/Pt/Au (1/35/275 nm) metalization sequence and an intermediate InAsSb contact layer with n-doping of 1 x 10(20) cm(-3) ( also Te). The high doping level is achieved during growth, so in-diffusion of dopants is not required. To reduce the impact of the native oxide layer we remove it in a sputter-etching process using Ar ions and afterwards deposit the metalization in the same chamber. No annealing is necessary to achieve ohmic IV-characteristics with a resistivity as low as 5.1 x 10(-6) Omega cm(2). It improves to 3.3 x 10(-6) Omega cm(2) after annealing at 350 degrees C for 90 s. The resistivity slightly increases for deeper etching of the native oxide, which is probably due to surface damage induced during the sputter-etching process.